NGC 2261 Hubble's variable nebula

There are only a handfull of nebulae which vary in brightness over shorter periods than hundreds of years. From my experience so far, Hubble's is much the easiest to photograph. It is in the constellation of Monoceros.

The star at the apex of this nebula is denoted R Monocerotis. That means it was the first known variable star in the constellation of Monoceros. It varies between about magnitudes 10 and 12. A possibility is that the brightness of the nebula follows the brightness of the star, after some time delay. I believe that connection has not been proved however.